The Iraqi air force struck back at the militant group ISIS, the Islamic State in Iraq and Syria, killing more than 200 militants, Iraqi state TV reported Monday morning. The air raids took place in Saqlawiyah, northwest of Fallujah, according to a graphic run by state TV.

ISIS has been ruthlessly fighting to take control of Iraq and has apparently posted chilling photos on jihadi Internet forums seeming to show the executions of Iraqi security forces.

CNN cannot independently confirm the authenticity of the images purportedly posted by ISIS. CNN is examining the terrain in the images, some of the signage on buildings in several of the pictures and the uniforms of the apparent victims. Those details suggest the photos are real and were taken in Iraq.

A caption on some of the images reads: "apostates heading to their hole of doom."

ISIS, an al Qaeda splinter group, wants to establish a caliphate, or Islamic state, that would stretch from Iraq into northern Syria. The group has had substantial success in Syria battling Syrian President Bashar al-Assad's security forces.

On Friday, a tweet on what was claimed to be an ISIS Twitter account claimed that its members killed at least 1,700 Shiites. CNN was unable to verify the authenticity of the account, and the account appeared to have been taken down Sunday.

JUST WATCHED

Meet the terrorists who scare al Qaeda

MUST WATCH

JUST WATCHED

Iraqi commander: 'There will be blood'

MUST WATCH

Iraqi commander: 'There will be blood'01:31

In a statement, the U.S. State Department condemned the claim by ISIS, also known as ISIL, the Islamic State of Iraq and the Levant.

"The claim by the Islamic State of Iraq and the Levant (ISIL) that it has massacred 1700 Iraqi Shia air force recruits in Tikrit is horrifying and a true depiction of the bloodlust that these terrorists represent. While we cannot confirm these reports, one of the primary goals of ISIL is to set fear into the hearts of all Iraqis and drive sectarian division among its people," part of the statement read. "Terrorists who can commit such heinous acts are a shared enemy of the United States, Iraq, and the international community. "

The militants' quick advance in Iraq has been helped by many Sunnis who feel that the Shiite-dominated government has marginalized them.

ISIS seized Iraq's second-largest city, Mosul, last week and has threatened to march on Baghdad, Iraq's capital and largest city.

But "Mosul didn't fall," a defiant Iraqi Prime Minister Nuri al-Maliki told military leaders in Baghdad in a speech televised Sunday on state TV. "The ones who have fallen are the politicians who have bet against Iraq." The Prime Minister said, "We will not allow anyone to divide the Iraqi people."

Al-Maliki called on his top brass and soldiers to march and fight against ISIS, while criticizing Iraqi politicians conspiring against their homeland and Iraqi soldiers who have refused to continue to fight when confronted by ISIS.

"We will march on every inch, with all our weapons, with all our will and faith, so we can liberate and cleanse every inch of Iraq -- from the southernmost point to the furthest point in the north," he exhorted the military leaders.

Wounded passengers are treated following a suicide bombing at the Brussels Airport on March 22, 2016. The attacks on the airport and a subway killed 32 people and wounded more than 300. ISIS claims its "fighters" launched the attacks in the Belgian capital.

Hide Caption

1 of 68

Photos:The ISIS terror threat

Syrians gather at the site of a double car bomb attack in the Al-Zahraa neighborhood of the Homs, Syria, on February 21, 2016. Multiple attacks in Homs and southern Damascus kill at least 122 and injure scores, according to the state-run SANA news agency. ISIS claimed responsibility.

Hide Caption

2 of 68

Photos:The ISIS terror threat

Syrian pro-government forces gather at the site of a deadly triple bombing Sunday, January 31, in the Damascus suburb of Sayeda Zeynab. ISIS claimed responsibility for the attack, according to a statement circulating online from supporters of the terrorist group.

Wounded people are helped outside the Bataclan concert hall in Paris following a series of coordinated attacks in the city on Friday, November 13. The militant group ISIS claimed responsibility for the attacks, which killed at least 130 people and wounded hundreds more.

Hide Caption

6 of 68

Photos:The ISIS terror threat

Emergency personnel and civilians gather at the site of a twin suicide bombing in Beirut, Lebanon, on Thursday, November 12. The bombings killed at least 43 people and wounded more than 200 more. ISIS appeared to claim responsibility in a statement posted on social media.

Hide Caption

7 of 68

Photos:The ISIS terror threat

Smoke rises over the northern Iraqi town of Sinjar on November 12. Kurdish Iraqi fighters, backed by a U.S.-led air campaign, retook the strategic town, which ISIS militants overran last year. ISIS wants to create an Islamic state across Sunni areas of Iraq and Syria.

Hide Caption

8 of 68

Photos:The ISIS terror threat

Syrian government troops walk inside the Kweiras air base on Wednesday, November 11, after they broke a siege imposed by ISIS militants.

Hide Caption

9 of 68

Photos:The ISIS terror threat

Members of the Egyptian military approach the wreckage of a Russian passenger plane Sunday, November 1, in Hassana, Egypt. The plane crashed the day before, killing all 224 people on board. ISIS claimed responsibility for downing the plane, but the group's claim wasn't immediately verified.

Hide Caption

10 of 68

Photos:The ISIS terror threat

An explosion rocks Kobani, Syria, during a reported car bomb attack by ISIS militants on Tuesday, October 20.

Hide Caption

11 of 68

Photos:The ISIS terror threat

Shiite fighters, fighting alongside Iraqi government forces, fire a rocket at ISIS militants as they advance toward the center of Baiji, Iraq, on Monday, October 19.

Hide Caption

12 of 68

Photos:The ISIS terror threat

Smoke rises above a damaged building in Ramadi, Iraq, following a coalition airstrike against ISIS positions on Saturday, August 15.

Hide Caption

13 of 68

Photos:The ISIS terror threat

Iraqi men look at damage following a bomb explosion that targeted a vegetable market in Baghdad on Thursday, August 13. ISIS claimed responsibility for the attack.

Hide Caption

14 of 68

Photos:The ISIS terror threat

In this image taken from social media, an ISIS fighter holds the group's flag after the militant group overran the Syrian town of al-Qaryatayn on Thursday, August 6, the London-based Syrian Observatory for Human Rights reported. ISIS uses modern tools such as social media to promote reactionary politics and religious fundamentalism. Fighters are destroying holy sites and valuable antiquities even as their leaders propagate a return to the early days of Islam.

Hide Caption

15 of 68

Photos:The ISIS terror threat

An ISIS fighter poses with spoils purportedly taken after capturing the Syrian town of al-Qaryatayn.

Hide Caption

16 of 68

Photos:The ISIS terror threat

Smoke rises as Iraqi security forces bomb ISIS positions in the eastern suburbs of Ramadi, Iraq, on August 6.

Hide Caption

17 of 68

Photos:The ISIS terror threat

Buildings reduced to piles of debris can be seen in the eastern suburbs of Ramadi on August 6.

Hide Caption

18 of 68

Photos:The ISIS terror threat

The governor of the Asir region in Saudi Arabia, Prince Faisal bin Khaled bin Abdulaziz, left, visits a man who was wounded in a suicide bombing attack on a mosque in Abha, Saudi Arabia, on August 6. ISIS claimed responsibility for the explosion, which killed at least 13 people and injured nine others.

Hide Caption

19 of 68

Photos:The ISIS terror threat

Saudi officials and investigators check the inside of the mosque on August 6.

Hide Caption

20 of 68

Photos:The ISIS terror threat

Mourners in Gaziantep, Turkey, grieve over a coffin Tuesday, July 21, during a funeral ceremony for the victims of a suspected ISIS suicide bomb attack. That bombing killed at least 31 people in Suruc, a Turkish town that borders Syria. Turkish authorities blamed ISIS for the attack.

Hide Caption

21 of 68

Photos:The ISIS terror threat

Protesters in Istanbul carry anti-ISIS banners and flags to show support for victims of the Suruc suicide blast during a demonstration on Monday, July 20.

Hide Caption

22 of 68

Photos:The ISIS terror threat

People in Ashmoun, Egypt, carry the coffin for 1st Lt. Mohammed Ashraf, who was killed when the ISIS militant group attacked Egyptian military checkpoints on Wednesday, July 1. At least 17 soldiers were reportedly killed, and 30 were injured.

Hide Caption

23 of 68

Photos:The ISIS terror threat

Syrians wait near the Turkish border during clashes between ISIS and Kurdish armed groups in Kobani, Syria, on Thursday, June 25. The photo was taken in Sanliurfa, Turkey. ISIS militants disguised as Kurdish security forces infiltrated Kobani on Thursday and killed "many civilians," said a spokesman for the Kurds in Kobani.

Hide Caption

24 of 68

Photos:The ISIS terror threat

Residents examine a damaged mosque after an Iraqi Air Force bombing in the ISIS-seized city of Falluja, Iraq, on Sunday, May 31. At least six were killed and nine others wounded during the bombing.

Hide Caption

25 of 68

Photos:The ISIS terror threat

People search through debris after an explosion at a Shiite mosque in Qatif, Saudi Arabia, on Friday, May 22. ISIS claimed responsibility for the attack, according to tweets from ISIS supporters, which included a formal statement from ISIS detailing the operation.

Hide Caption

26 of 68

Photos:The ISIS terror threat

Iraqi soldiers fire their weapons toward ISIS group positions in the Garma district, west of the Iraqi capital of Baghdad, on Sunday, April 26. Pro-government forces said they had recently made advances on areas held by Islamist jihadists.

Hide Caption

27 of 68

Photos:The ISIS terror threat

A member of Afghanistan's security forces stands at the site where a suicide bomber on a motorbike blew himself up in front of the Kabul Bank in Jalalabad, Afghanistan, on Saturday, April 18. ISIS claimed responsibility for the attack. The explosion killed at least 33 people and injured more than 100 others, a public health spokesman said.

Hide Caption

28 of 68

Photos:The ISIS terror threat

Iraqi counterterrorism forces patrol in Ramadi on April 18.

Hide Caption

29 of 68

Photos:The ISIS terror threat

Thousands of Iraqis cross a bridge over the Euphrates River to Baghdad as they flee Ramadi on Friday, April 17.

Hide Caption

30 of 68

Photos:The ISIS terror threat

Yazidis embrace after being released by ISIS south of Kirkuk, Iraq, on Wednesday, April 8. ISIS released more than 200 Yazidis, a minority group whose members were killed, captured and displaced when the Islamist terror organization overtook their towns in northern Iraq last summer, officials said.

Hide Caption

31 of 68

Photos:The ISIS terror threat

Kurdish Peshmerga forces help Yazidis as they arrive at a medical center in Altun Kupri, Iraq, on April 8.

Hide Caption

32 of 68

Photos:The ISIS terror threat

A Yazidi woman mourns for the death of her husband and children by ISIS after being released south of Kirkuk on April 8. ISIS is known for killing dozens of people at a time and carrying out public executions, crucifixions and other acts.

Hide Caption

33 of 68

Photos:The ISIS terror threat

People in Tikrit inspect what used to be a palace of former President Saddam Hussein on April 3.

Hide Caption

34 of 68

Photos:The ISIS terror threat

On April 1, Shiite militiamen celebrate the retaking of Tikrit, which had been under ISIS control since June. The push into Tikrit came days after U.S.-led airstrikes targeted ISIS bases around the city.

Hide Caption

35 of 68

Photos:The ISIS terror threat

Iraqi security forces launch a rocket against ISIS positions in Tikrit on Monday, March 30.

Hide Caption

36 of 68

Photos:The ISIS terror threat

The parents of 19-year-old Mohammed Musallam react at the family's home in the East Jerusalem Jewish settlement of Neve Yaakov on Tuesday, March 10. ISIS released a video purportedly showing a young boy executing Musallam, an Israeli citizen of Palestinian descent who ISIS claimed infiltrated the group in Syria to spy for the Jewish state. Musallam's family told CNN that he had no ties with the Mossad, Israel's spy agency, and had, in fact, been recruited by ISIS.

Hide Caption

37 of 68

Photos:The ISIS terror threat

Iraqi Shiite fighters cover their ears as a rocket is launched during a clash with ISIS militants in the town of Al-Alam, Iraq, on Monday, March 9.

Hide Caption

38 of 68

Photos:The ISIS terror threat

Displaced Assyrian women who fled their homes due to ISIS attacks pray at a church on the outskirts of Damascus, Syria, on Sunday, March 1. ISIS militants abducted at least 220 Assyrians in Syria.

Hide Caption

39 of 68

Photos:The ISIS terror threat

Safi al-Kasasbeh, right, receives condolences from tribal leaders at his home village near Karak, Jordan, on Wednesday, February 4. Al-Kasasbeh's son, Jordanian pilot Moath al-Kasasbeh, was burned alive in a video that was recently released by ISIS militants. Jordan is one of a handful of Middle Eastern nations taking part in the U.S.-led military coalition against ISIS.

Hide Caption

40 of 68

Photos:The ISIS terror threat

A Kurdish marksman looks over a destroyed area of Kobani on Friday, January 30, after the city had been liberated from the ISIS militant group. The Syrian city, also known as Ayn al-Arab, had been under assault by ISIS since mid-September.

Hide Caption

41 of 68

Photos:The ISIS terror threat

Kurdish people celebrate in Suruc, Turkey, near the Turkish-Syrian border, after ISIS militants were expelled from Kobani on Tuesday, January 27.

Hide Caption

42 of 68

Photos:The ISIS terror threat

Collapsed buildings are seen in Kobani on January 27 after Kurdish forces took control of the town from ISIS.

Hide Caption

43 of 68

Photos:The ISIS terror threat

Junko Ishido, mother of Japanese journalist Kenji Goto, reacts during a news conference in Tokyo on Friday, January 23. ISIS would later kill Goto and another Japanese hostage, Haruna Yukawa.

Hide Caption

44 of 68

Photos:The ISIS terror threat

ISIS militants are seen through a rifle's scope during clashes with Peshmerga fighters in Mosul, Iraq, on Wednesday, January 21.

Hide Caption

45 of 68

Photos:The ISIS terror threat

An elderly Yazidi man arrives in Kirkuk after being released by ISIS on Saturday, January 17. The militant group released about 200 Yazidis who were held captive for five months in Iraq. Almost all of the freed prisoners were in poor health and bore signs of abuse and neglect, Kurdish officials said.

Hide Caption

46 of 68

Photos:The ISIS terror threat

Smoke billows behind an ISIS sign during an Iraqi military operation to regain control of the town of Sadiyah, about 95 kilometers (60 miles) north of Baghdad, on Tuesday, November 25.

Hide Caption

47 of 68

Photos:The ISIS terror threat

Fighters from the Free Syrian Army and the Kurdish People's Protection Units join forces to fight ISIS in Kobani on Wednesday, November 19.

Hide Caption

48 of 68

Photos:The ISIS terror threat

A picture taken from Turkey shows smoke rising after ISIS militants fired mortar shells toward an area controlled by Syrian Kurdish fighters near Kobani on Monday, November 3.

Hide Caption

49 of 68

Photos:The ISIS terror threat

Iraqi special forces search a house in Jurf al-Sakhar, Iraq, on Thursday, October 30, after retaking the area from ISIS.

Hide Caption

50 of 68

Photos:The ISIS terror threat

ISIS militants stand near the site of an airstrike near the Turkey-Syria border on Thursday, October 23. The United States and several Arab nations have been bombing ISIS targets in Syria to take out the militant group's ability to command, train and resupply its fighters.

Hide Caption

51 of 68

Photos:The ISIS terror threat

Kurdish fighters walk to positions as they combat ISIS forces in Kobani on Sunday, October 19.

Hide Caption

52 of 68

Photos:The ISIS terror threat

Heavy smoke rises in Kobani following an airstrike by the U.S.-led coalition on October 18.

Hide Caption

53 of 68

Photos:The ISIS terror threat

Cundi Minaz, a female Kurdish fighter, is buried in a cemetery in the southeastern Turkish town of Suruc on Tuesday, October 14. Minaz was reportedly killed during clashes with ISIS militants in nearby Kobani.

Hide Caption

54 of 68

Photos:The ISIS terror threat

Kiymet Ergun, a Syrian Kurd, celebrates in Mursitpinar, Turkey, after an airstrike by the U.S.-led coalition in Kobani on Monday, October 13.

Hide Caption

55 of 68

Photos:The ISIS terror threat

Alleged ISIS militants stand next to an ISIS flag atop a hill in Kobani on Monday, October 6.

Hide Caption

56 of 68

Photos:The ISIS terror threat

A Kurdish Peshmerga soldier who was wounded in a battle with ISIS is wheeled to the Zakho Emergency Hospital in Duhuk, Iraq, on Tuesday, September 30.

Hide Caption

57 of 68

Photos:The ISIS terror threat

Syrian Kurds wait near a border crossing in Suruc as they wait to return to their homes in Kobani on Sunday, September 28.

Hide Caption

58 of 68

Photos:The ISIS terror threat

A elderly man is carried after crossing the Syria-Turkey border near Suruc on Saturday, September 20.

Kurdish Peshmerga fighters fire at ISIS militant positions from their position on the top of Mount Zardak, east of Mosul, Iraq, on Tuesday, September 9.

Hide Caption

61 of 68

Photos:The ISIS terror threat

Displaced Iraqis receive clothes from a charity at a refugee camp near Feeshkhabour, Iraq, on Tuesday, August 19.

Hide Caption

62 of 68

Photos:The ISIS terror threat

Aziza Hamid, a 15-year-old Iraqi girl, cries for her father while she and some other Yazidi people are flown to safety Monday, August 11, after a dramatic rescue operation at Iraq's Mount Sinjar. A CNN crew was on the flight, which took diapers, milk, water and food to the site where as many as 70,000 people were trapped by ISIS. But only a few of them were able to fly back on the helicopter with the Iraqi Air Force and Kurdish Peshmerga fighters.

Hide Caption

63 of 68

Photos:The ISIS terror threat

Thousands of Yazidis are escorted to safety by Kurdish Peshmerga forces and a People's Protection Unit in Mosul on Saturday, August 9.

Hide Caption

64 of 68

Photos:The ISIS terror threat

Thousands of Yazidi and Christian people flee Mosul on Wednesday, August 6, after the latest wave of ISIS advances.

Hide Caption

65 of 68

Photos:The ISIS terror threat

A Baiji oil refinery burns after an alleged ISIS attack in northern Selahaddin, Iraq, on Thursday, July 31.

Hide Caption

66 of 68

Photos:The ISIS terror threat

A Syrian rebel fighter lies on a stretcher at a makeshift hospital in Douma, Syria, on Wednesday, July 9. He was reportedly injured while fighting ISIS militants.

Hide Caption

67 of 68

Photos:The ISIS terror threat

Children stand next to a burnt vehicle during clashes between Iraqi security forces and ISIS militants in Mosul on Tuesday, June 10.

Hide Caption

68 of 68

The northwest Iraqi city of Tal Afar fell to ISIS, according to Iraqi Gen. Mohammed al-Quraishi. Many Tal Afar residents -- ethnic minority Shiite Turkmen -- fled the fighting north toward Iraq's Kurdish region. Tal Afar is in Nineveh province, midway between the country's border with Syria and Mosul, north of Baghdad.

Before Iraqi security forces lost Tal Afar, several mortar rounds landed on a busy area in the town and killed at least seven and wounded 33 people, security officials in Baghdad and Tal Afar told CNN.

Also Sunday, ISIS gained control of two villages in Adhaim, in its first push into Diyala province, northeast of Baghdad.

On top of that, Iraqi security forces and gunmen believed to be ISIS clashed near al-Khalis, about 18 miles from Diyala's capital, Baquba, al-Khalis police officials told CNN. Three mortar rounds landed near a recruitment center opened recently for volunteers to help the Iraqi army fight against ISIS.

Baquba is about 37 miles northeast of Baghdad. Baquba is an ethnically-mixed city, though Sunnis represent a slight majority.

Given Baquba's proximity to Baghdad, if Baquba were to fall, it could give ISIS militants three-pronged access to Baghdad -- from Anbar province to the west, Ninevah and Salahuddin provinces to the north and from Diyala province from the northeast.

Meanwhile, on Sunday, CNN Senior International Correspondent Arwa Damon was in the Iraqi Kurdish province of Kirkuk, where last Thursday militants took control of two villages.

She asked the local governor, Dr. Najmaldin Karim, whether the United States should launch airstrikes to help fight back ISIS.

"I think they know how to do it, but blanket bombing is not going to work here," Karim said, explaining that that approach ignores the fact that ISIS is too blended into the civilian population in Kirkuk and innocent people could die. But there should be targeted bombing in both Iraq and Syria, he said.

"I don't think anyone is safe from these people," said Karim.

Partial staff relocation at U.S. Embassy

Between 50 and 100 U.S. Marines and U.S. Army personnel have arrived at the U.S. Embassy in Baghdad, a U.S. official told CNN on Sunday.

A U.S official acknowledged to CNN that the additional embassy security personnel being added include U.S. Marines who specialize in embassy protection during high-threat conditions.

The U.S. invaded Iraq in 2003. American military forces ended their withdrawal from the country in December 2011.

At the time of the U.S. drawdown, Iraq's leadership had agreed that a residual U.S. military presence was desirable, but the talks broke down over the prickly issue of legal immunity for U.S. troops in Iraq.

The Obama administration had said any deal to keep U.S. troops in Iraq beyond the withdrawal deadline would require a guarantee of legal protection for American soldiers. But the Iraqis refused to agree to that, opening up the prospect of American troops being tried in Iraqi courts and subjected to Iraqi punishment.

This week, President Barack Obama continued to consider options with regard to the situation in Iraq but ruled out sending troops into the country.

On Sunday, U.S. State Department spokeswoman Jen Psaki said that some U.S. security personnel will be added to the staff at the U.S. Embassy in Baghdad and other staff members will be temporarily relocated to consular offices in Basra and Irbil and to the Iraq Support Unit in Amman, Jordan.

A "substantial majority of the U.S. Embassy presence in Iraq will remain in place," Psaki said in a statement, and "the Embassy will be fully equipped to carry out its national security mission."

Pentagon Press Secretary Rear Adm. John Kirby said that a "small number of Defense Department personnel" are augmenting State Department security assets in Baghdad. Kirby said that the relocation of some embassy personnel is being done with commercial, charter and State Department aircraft flights.

The U.S. military can airlift people if the State Department asks for that, Kirby said.

The State Department is warning U.S. citizens against "all but essential travel to Iraq." The official travel warning says U.S. citizens in Iraq "remain at high risk for kidnapping and terrorist violence."

While that continues, Iran has recently entered the fray, according to a senior security official in Baghdad who spoke to CNN on Friday. That official said that in recent days, Iran has sent about 500 Iranian Revolutionary Guard troops to fight alongside Iraqi government security forces in Iraq's Diyala province.

However, Iranian officials, including President Hassan Rouhani, denied reports that some of its elite forces are in Iraq to help bolster al-Maliki, a fellow Shiite.

"If the Iraqi government wants us to help, we will consider it," Rouhani said, according to an English translation of his remarks Saturday in Farsi by state-run Press TV.

But, he said, "so far they have not asked specifically for help," and added that Iran could give strategic guidance if requested.

The Obama administration is exploring possible direct talks with Iran over the deteriorating situation in Iraq, two senior U.S. officials tell CNN.

Both officials ruled out any type of teaming up with Iran because the United States and Iran don't have a lot of common interests -- other than a stable Iraq.

The United States is wary of furthering Iran's already considerable influence in Iraq. The Shiite Iranian regime is al-Malaki's closest ally in the region. Additionally the administration is concerned appearing to team up with Iran would both alienate Iraq's Sunni majority and worry Sunni allies of the United States in the region.

The State Department statement said the United States "will do its part to help Iraq move beyond this crisis," and a senior State Department officer told CNN that Kerry spoke to his counterparts from Jordan, the UAE, Saudi Arabia and Qatar to discuss the threat posed by ISIS.

The administration has not yet determined what the mechanism would be for talking to Iran, the senior U.S. officials said.

Ex-U.S. ambassador: Kerry should go to Iraq

On Sunday U.S. Sen. Lindsey Graham argued on CNN's "State of the Union" for more intervention in Iraq.

The South Carolina Republican, a frequent critic of the Obama administration's approach to foreign policy, called Obama "stubborn-headed," "delusional" and "detached" over his decision on how to react to the unfolding crisis.

"Time is running out to turn this around," Graham said. "Get involved with air power. Stop the march toward Baghdad. Deal with Syria. But get a new government (in Iraq) in place as quickly as you can that will bring the Iraqis back together for a counteroffensive."

Ryan Crocker, the U.S. ambassador to Iraq from 2007 to 2009, told CNN's Fareed Zakaria on Sunday that he thinks Secretary of State John Kerry should fly to Iraq immediately.

"We need the secretary of state out there in Baghdad right now," Crocker said. "We need the President on the phone to the Iraqi leadership because the reality is the Iraqis are not in a position ... they were not in a position when I was there, they are not in a position now, to work out hard compromises on their own."

The United States is the "middleman among Sunni, Shia and Kurds," Crocker said. "Ambassadors can go just so far."

Crocker, now the dean of the George Bush School of Government & Public Service at Texas A&M University, said he would support "very carefully targeted airstrikes" in conjuction with high-level diplomacy.

"We have got to help the Iraqis come together," Crocker urged, "in a unified fashion to confront a common threat."